In a large bowl, combine the dried kidney beans, 1 1/2 tablespoons kosher salt, and 6 cups of water. Stir until the salt is dissolved. Leave undisturbed at room temperature for at least 8 hours, up to 16. Drain and rinse.

Heat the bacon fat in a large dutch oven (at least 5 qt) over medium-high heat. Once the fat is hot, add the sliced sausage and cook, stirring occasionally, until browned. Using a slotted spoon, transfer the browned sausage to a plate.

Add the onions, bell pepper, and celery to the pot and cook the veggies until they're starting to brown. Add the garlic, paprika, thyme, and cayenne and cook for 2 more minutes.

Return the sausage to the pot and add the chicken stock. Use a wooden spoon to scrape up any browned bits. Add the Worcestershire, soaked beans, ham hock, and bay leaves and bring to a simmer. Cover, reduce the heat to medium-low, and cook for 2 hours.

Remove the lid and simmer for another 30-25 minutes, until the beans are very creamy. Remove the ham hock, shred the meat (discard the bones), and return the meat to the beans. Season to taste with salt and pepper and add a bit of sherry vinegar to taste for brightness.

Serve over buttery white rice topped with green onions and hot sauce.